Display substrate, method for manufacturing the same and display device

ABSTRACT

A display substrate, a method for manufacturing the same and a display device are provided. The display substrate includes a black matrix disposed between adjacent pixels, and a sidewall of the black matrix is a concave curved surface. Since the sidewall of the black matrix is formed as a concave curved surface, when color film droplets in one sub-pixel splash to the sidewall of the black matrix in forming of a color film, the droplets can return into the sub-pixel along the curved surface, thereby avoiding contamination to adjacent pixels by the droplets splashing, and ensuring substrate yield.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage entry of PCT/CN2016/076253 filed Mar. 14, 2016, which claims priority to Chinese Patent Application No. 201510259953.4 filed on May 20, 2015, the disclosures of which are incorporated herein in their entirety as part of the present application.

BACKGROUND

Exemplary embodiments of the present disclosure relate to a display substrate and a method for manufacturing the same, and a display device.

In the field of the active-matrix organic light emitting diode (AMOLED) display, because of its high response speed, high color gamut, high contrast, wide viewing angle, ultra-thin, low power consumption and so on, so it becomes the hot spot of modern display research.

In particular, the top emission structure of WOLED display has advantage of a high aperture ratio, since a light is emitted from the other end of the active matrix such that there is no blocking of the metal wiring to the light emission of the OLED. The top emission structure of the AMOLED can avoid a UV (ultraviolet light) on the impact of the OLED based on the printing process through directly forming a color film on the OLED. A black matrix (BM) in the color film has a thickness of higher than 1 μm, and the slope angle is generally between 30 to 60 degrees (shown in FIG. 1), but compared with the traditional printing process in which the color film only needs a thickness of 200-300 nm when manufacturing the OLED, the thickness of the color film should be up to a micron level when ensuring a color saturation, in the case of the used droplet is larger when printing the color film, splashing of the droplets in the direction of the slope of BC is more likely to occur, and contamination between adjacent pixels tends to be caused.

BRIEF DESCRIPTION

Embodiments of the present disclosure provide a display substrate and a manufacturing method thereof and a corresponding display device, so as to avoid contamination of adjacent pixels by droplets during a color film printing.

According to a first aspect of the present disclosure, a display substrate is provided, which includes a black matrix disposed between adjacent pixels, wherein a sidewall of the black matrix is a concave curved surface.

According to an embodiment of the present disclosure, a material of the black matrix includes a negative photoresist.

According to an embodiment of the present disclosure, the black matrix includes a first insulating layer, a second insulating layer disposed on the first insulating layer, a third insulating layer disposed on the second insulating layer, and a light shielding layer disposed on the third insulating layer, wherein, an etched rate of the first insulating layer is greater than an etched rate of the second insulating layer, and the etched rate of the second insulating layer is greater than an etched rate of the third insulating layer.

According to an embodiment of the present disclosure, the black matrix further includes a lower second insulating layer disposed under the first insulating layer, and a lower third insulating layer disposed under the lower second insulating layer.

According to an embodiment of the present disclosure, the first insulating layer, the second insulating layer and the third insulating layer are etched by a dry etching process. Alternatively, the first insulating layer, the second insulating layer, the third insulating layer, the lower second insulating layer and the lower third insulating layer are etched by a dry etching process.

According to an embodiment of the present disclosure, the first insulating layer is formed by a silicon nitride, the second insulating layer is formed by a silicon oxynitride, and the third insulating layer is formed by a silicon oxide. Alternatively, the first insulating layer is formed by a silicon nitride, the second insulating layer and the lower second insulating layer are formed by a silicon oxynitride, and the third insulating layer and the lower third insulating layer is formed by a silicon oxide.

According to an embodiment of the present disclosure, the display substrate further includes an encapsulation layer disposed under the black matrix for encapsulating an organic light emitting diode, and a blocking layer disposed between the black matrix and the encapsulation layer for preventing the encapsulation layer from being etched by a dry etch process.

According to an embodiment of the present disclosure, the display substrate further includes an absorbing layer disposed on the black matrix for absorbing an organic solvent, water and/or a liquid for forming sub-pixels.

According to a second aspect of the present disclosure, a display device including the display substrate described as above is also provided.

According to a third aspect of the present disclosure, a method for manufacturing a display substrate is also provided, which includes forming a black matrix between adjacent pixels, such that a sidewall of the black matrix is a concave curved surface.

According to an embodiment of the present disclosure, forming the black matrix between adjacent pixels includes forming a black matrix layer using a negative photoresist, heating the black matrix layer to dry an organic solvent in the black matrix layer, exposing the black matrix layer, and developing the black matrix layer to form the black matrix.

According to an embodiment of the present disclosure, forming the black matrix between adjacent pixels includes forming a first insulating layer, forming a second insulating layer on the first insulating layer, forming a third insulating layer on the second insulating layer, and forming a light shielding layer on the third insulating layer, wherein, an etched rate of the first insulating layer is greater than an etched rate of the second insulating layer, and the etched rate of the second insulating layer is greater than an etched rate of the third insulating layer.

According to an embodiment of the present disclosure, before forming the first insulating layer, further includes forming a lower third insulating layer, and forming a lower second insulating layer on the lower third insulating layer, the first insulating layer is formed on the lower second insulating layer.

According to an embodiment of the present disclosure, the first insulating layer is formed by a silicon nitride, the second insulating layer is formed by a silicon oxynitride, and the third insulating layer is formed by a silicon oxide. Alternatively, the first insulating layer is formed by a silicon nitride, the second insulating layer and the lower second insulating layer are formed by a silicon oxynitride, and the third insulating layer and the lower third insulating layer are formed by a silicon oxide.

According to an embodiment of the present disclosure, the method for manufacturing the display substrate further includes forming a blocking layer between the black matrix and the encapsulation layer to prevent the encapsulation layer being etched by a dry etch process, wherein the encapsulation layer is disposed under the black matrix to encapsulate an organic light emitting diode.

According to an embodiment of the present disclosure, the method for manufacturing the display substrate further includes forming an absorbing layer on the black matrix to absorb an organic solvent, water and/or a liquid for forming sub-pixels.

According to an embodiment of the present disclosure, by forming the sidewall of the black matrix as a concave curved surface, when color film droplets in one sub-pixel splash to the sidewall of the black matrix in the formation of a color film, the droplets can return into the sub-pixel along the curved surface, so as to avoid contamination to adjacent pixels by the droplets splashing, and ensure substrate yield.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in embodiments of the present disclosure or in the prior art, the following drawings to be used in the description of the embodiments or in the prior art will be briefly introduced below. Apparently, the drawings in the following description are only for some embodiments of the present disclosure, those of ordinary skill in the art may also obtain other drawings from these drawings, without creative efforts.

FIG. 1 is a schematic view illustrating a structure of a black matrix in the prior art;

FIG. 2 is a schematic view illustrating a structure of a display substrate according to one embodiment of the present disclosure;

FIG. 3 is a schematic view illustrating droplets splashing in the prior art;

FIG. 4 is a schematic view illustrating droplets splashing according to one embodiment of the present disclosure;

FIG. 5 is a schematic view illustrating a structure of a black matrix according to one embodiment of the present disclosure;

FIG. 6 is a schematic view illustrating a structure of a black matrix according to another embodiment of the present disclosure;

FIG. 7 is a schematic view illustrating a structure of a black matrix according to yet another embodiment of the present disclosure; and

FIG. 8 is a flowchart illustrating a method for manufacturing a display substrate according to one embodiment of the present disclosure.

DETAILED DESCRIPTION

The technical solution in embodiments of the present disclosure will be clearly and completely described in combination with the drawings in the embodiments of the present disclosure. Apparently, the described embodiments are merely part of the embodiments of the present disclosure, instead of all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without creative work fall within the scope of the disclosure. As shown in FIG. 2, a display substrate according to one embodiment of the present disclosure includes a black matrix 1 disposed between adjacent pixels, in which the black matrix 1 has a sidewall of concave curved surface.

Since a sidewall of the black matrix is a concave curved surface, when color film droplets in sub-pixels of a first pixel region 5 splash to the sidewall of the black matrix 1 in forming of a color film, the droplets can return into the sub-pixels along the curved surface and will not enter into sub-pixels of a second pixel region 6. Accordingly, contamination of the first pixel region 5 can also be prevented when the droplets are dropped into the sub-pixels of the second pixel region 6.

The droplets splashing according to an embodiment of the present disclosure is shown in FIG. 4, and compared with the droplets splashing in the prior art (shown as FIG. 3), the droplets splashing according to an embodiment of the present disclosure has a reduced range, and the droplets splashing also has a decreased height, thereby ensuring pure color of each sub-pixel in the formed color film, improving the display effect and ensuring the substrate yield.

It is to be noted that the display substrate in the present embodiment includes a thin film transistor, in addition to the black matrix 1. Specifically, the display substrate according to an embodiment of the present disclosure may include a gate electrode, a gate insulating layer, an active layer, an etching blocking layer, a source electrode, a drain electrode, a passivation layer and the like, and may further include an organic light emitting layer, which will not repeated again here.

According to an embodiment of the present disclosure, a material of the black matrix 1 includes a negative photoresist.

The patterns of the black matrix 1 may be formed by using a UV (ultraviolet light) irradiation, and regions of the negative photoresist irradiated by UV may be cured and remain. When the black matrix 1 is formed, since exposure holes on a mask film are very small, light diffraction may be caused, and thus a larger area of the material of the black matrix is irradiated, thereby a larger area (which is greater than the area of the exposure hole) of black matrix is cured. The material of the black matrix has a strong barrier to light, and diffracted light is difficult to transmit into the deeper black matrix material, thus deeper black matrix material can only be cured to a black matrix equivalent to the area of the exposure hole.

The lowermost material of the black matrix has a higher amount of heat due to contacting with a heating plate (which is used to dry the organic solvent during the exposure), the organic solvent evaporates more quickly and the remaining material of the black matrix is more, such that a wider black matrix can be formed through the exposure, and thus the sidewall of concave curved surface having wider upper and lower portions and a narrower middle portion is formed.

As shown in FIG. 5, the black matrix 1 according to an embodiment of the present disclosure includes a first insulating layer 11, a second insulating layer 12 disposed on the first insulating layer 11, a third insulating layer 13 disposed on the second insulating layer 12, and a light shielding layer 14 disposed on the third insulating layer 13, wherein, an etched rate of the first insulating layer 11 is greater than an etched rate of the second insulating layer 12, the etched rate of the second insulating layer 12 is greater than an etched rate of the third insulating layer 13, thereby forming a curved surface as shown at the right side of FIG. 5.

According to an embodiment of the present disclosure, the material of the first insulating layer 11 may be a silicon nitride SiNX, and the etched rate is 30 Angstroms (Å)/second, the material of the second insulating layer 12 may be a silicon oxynitride SiOYNX, and the etched rate is between 10 Å/second to 30 Å/second, and the material of the third insulating layer 13 may be a silicon oxide SiOX, and the etched rate is 10 Å/second. Since the etched rate of the first insulating layer 11 is fastest, the etched rate of the third insulating layer 13 is slowest, and the etched rate of the second insulating layer 12 is between the above two, thus when an etching is performed, the first insulating layer 11 is etched to the deepest depth, the third insulating layer 13 is etched to the shallowest depth and the second insulating layer 12 is etched to a depth between the above two, such that a sidewall recessed from the third insulating layer 13 toward the first insulating layer 11 is formed.

As shown in FIG. 6, the black matrix 1 according to an embodiment of the present disclosure further includes a lower second insulating layer 15 disposed under the first insulating layer 11, and a lower third insulating layer 16 disposed under the lower second insulating layer 15.

According to an embodiment of the present disclosure, the lower second insulating layer 15 and the second insulating layer 12 may be formed by same materials, and the lower third insulating layer 16 and the third insulating layer 13 may be formed by same materials.

The lower second insulating layer 15 and the lower third insulating layer 16 may be formed with a sidewall recessed from down to up to cooperate with the first insulating layer 11, the second insulating layer 12 and the third insulating layer 13, such that a more rounded sidewall can be formed to ensure that the droplets can still flow back to the target sub-pixel along the sidewall after the droplets splash to ensure the color of the target sub-pixel.

According to an embodiment of the present disclosure, the first insulating layer 11, the second insulating layer 12 and the third insulating layer 13 may be etched by a dry etching process, or the first insulating layer 11, the second insulating layer 12, the third insulating layer 13, the lower second insulating layer 15 and the lower third insulating layer 16 may be etched by a dry etching process.

The dry etching process may be performed through a gas, and in addition to etching the surface of the black matrix, the sidewalls of the black matrix 1 may be etched.

As shown in FIG. 7, according to an embodiment of the present disclosure, the display substrate formed with the black matrix 1 described as above may further includes an encapsulation layer 3 disposed under the black matrix 1 for encapsulating an organic light emitting diode, and a blocking layer 2 disposed between the black matrix 1 and the encapsulation layer 3 for preventing the encapsulation layer 3 from being etched by the dry etching process.

By providing the barrier layer 2, it is possible to avoid the encapsulation layer 3 from being etched by the dry etching gas, thereby facilitating the protection of the internal structure of the package.

According to an embodiment of the present disclosure, the display substrate formed with the black matrix 1 described as above may further includes an absorbing layer 4 disposed on the black matrix 1 for absorbing an organic solvent, water and/or a liquid for forming sub-pixels.

By providing the absorbing layer 4, it is possible to ensure that the liquid droplets sputtered on the black matrix 1 can also be absorbed, thereby further avoiding sputtering and contamination to other sub-pixels.

According to an embodiment of the present disclosure, a display device including the display substrate described as above is also provided.

It is to be noted that the display device in the present embodiment may be any product or component having a display function such as an electronic paper, a mobile phone, a tablet computer, a television set, a notebook computer, a digital photo frame, a navigator or the like.

A method for manufacturing a display substrate according to one embodiment of the present disclosure includes forming a black matrix 1 between adjacent pixels, such that a sidewall of the black matrix 1 is a concave curved surface.

According to an embodiment of the present disclosure, forming the black matrix 1 between adjacent pixels includes forming a black matrix layer using a negative photoresist, heating the black matrix layer to dry an organic solvent in the black matrix layer, exposing the black matrix layer; and developing the black matrix layer to form the black matrix 1.

As shown in FIG. 8, forming the black matrix 1 between adjacent pixels includes S1, forming a first insulating layer 11, S2, forming a second insulating layer 12 on the first insulating layer 11, S3, forming a third insulating layer 13 on the second insulating layer 12, and S4, forming a light shielding layer 14 on the third insulating layer 13, wherein, an etched rate of the first insulating layer 11 is greater than an etched rate of the second insulating layer 12, and the etched rate of the second insulating layer 12 is greater than an etched rate of the third insulating layer 13.

According to an embodiment of the present disclosure, before forming the first insulating layer 11, further including forming a lower third insulating layer 16, and forming a lower second insulating layer 15 on the lower third insulating layer 16, and the first insulating layer 11 is formed on the lower second insulating layer 15.

According to an embodiment of the present disclosure, forming the display substrate may further include forming a blocking layer 2 between the black matrix 1 and the encapsulation layer 3 to prevent the encapsulation layer 3 from being etched by a dry etching process, wherein the encapsulation layer 3 is disposed under the black matrix 1 to encapsulate an organic light emitting diode.

According to an embodiment of the present disclosure, forming the display substrate may further include forming an absorbing layer 4 on the black matrix 1 to absorb an organic solvent, water and/or a liquid for forming sub-pixels.

According to an embodiment of the present disclosure, the forming process employed in the processes described as above may include, for example, a film forming process such as deposition, sputtering and the like, and/or a patterning process such as etching.

The technical solution of the present disclosure has been described above in detail with reference to the accompanying drawings. In the prior art, droplets for forming sub-pixels may be sputtered into sub-pixels of other pixel regions in the forming of a color film, thereby contaminating the other sub-pixels. According to the technical solution of the present disclosure, by forming the sidewall of the black matrix as a concave curved surface, when color film droplets in one sub-pixel splash to the sidewall of the black matrix in the formation of a color film, the droplets can return into the sub-pixel along the curved surface, so as to avoid contamination to adjacent pixels by the droplets splashing, and ensure the substrate yield.

It is to be noted that the dimensions of the layers and regions in the drawings may be exaggerated for clarity of illustration. It is also to be understood that when an element or layer is referred to as being “on” another element or layer, it may be directly on the other element, or intervening layers may be present. In addition, it will be understood that when an element or layer is referred to as being “under” another element or layer, it may be directly under the other element, or more than one intervening layer or element may be present. In addition, it will also be understood that when a layer or element is referred to as being “between” two layers or two elements, it may be a single layer between the two layer or the two elements, or more than one intervening layer or element may be present.

In the present disclosure, the terms “first”, “second” and “third” are used for purposes of illustration only and are not to be taken as an indication or suggestion of relative importance. The term “a plurality of” refers to two or more than two, unless otherwise specifically defined.

The foregoing are only example embodiments of the disclosure and are not intended to be limiting of the disclosure, and those skilled in the art will understand that various changes and modifications may be made therein. Any modifications, equivalent substitutions, improvements and the like within the spirit and principles of the disclosure are intended to be included within the scope of the disclosure. 

What is claimed is:
 1. A display substrate, comprising: a black matrix disposed between adjacent pixels, wherein a sidewall of the black matrix is a concave curved surface.
 2. The display substrate of claim 1, wherein a material of the black matrix comprises a negative photoresist.
 3. The display substrate of claim 1, wherein the black matrix comprises: a first insulating layer; a second insulating layer disposed on the first insulating layer; a third insulating layer disposed on the second insulating layer; and a light shielding layer disposed on the third insulating layer, wherein an etched rate of the first insulating layer is greater than an etched rate of the second insulating layer, and wherein the etched rate of the second insulating layer is greater than an etched rate of the third insulating layer.
 4. The display substrate of claim 3, wherein the black matrix further comprises: a lower second insulating layer disposed under the first insulating layer; and a lower third insulating layer disposed under the lower second insulating layer.
 5. The display substrate of claim 3, wherein i) the first insulating layer, the second insulating layer, and the third insulating layer are etched by a dry etching process, or ii) the first insulating layer, the second insulating layer, the third insulating layer, the lower second insulating layer, and the lower third insulating layer are etched by a dry etching process.
 6. The display substrate of claim 3, wherein i) the first insulating layer is formed by a silicon nitride, the second insulating layer is formed by a silicon oxynitride, and the third insulating layer is formed by a silicon oxide, or ii) the first insulating layer is formed by a silicon nitride, the second insulating layer and the lower second insulating layer are formed by a silicon oxynitride, and the third insulating layer and the lower third insulating layer are formed by a silicon oxide.
 7. The display substrate of claim 1, further comprising: an encapsulation layer disposed under the black matrix for encapsulating an organic light emitting diode; and a blocking layer disposed between the black matrix and the encapsulation layer for preventing the encapsulation layer from being etched by a dry etching process.
 8. The display substrate of claim 1, further comprising: an absorbing layer disposed on the black matrix for absorbing an organic solvent, water and/or a liquid for forming sub-pixels.
 9. A display device, comprising the display substrate of claim
 1. 10. A method for manufacturing a display substrate, comprising: forming a black matrix between adjacent pixels, such that a sidewall of the black matrix is a concave curved surface.
 11. The method of claim 10, wherein forming the black matrix between adjacent pixels comprises: forming a black matrix layer using a negative photoresist; heating the black matrix layer to dry an organic solvent in the black matrix layer; exposing the black matrix layer; and developing the black matrix layer to form the black matrix.
 12. The method of claim 10, wherein forming the black matrix between adjacent pixels comprises: forming a first insulating layer; forming a second insulating layer on the first insulating layer; forming a third insulating layer on the second insulating layer; and forming a light shielding layer on the third insulating layer, wherein an etched rate of the first insulating layer is greater than an etched rate of the second insulating layer, and wherein the etched rate of the second insulating layer is greater than an etched rate of the third insulating layer.
 13. The method of claim 12, wherein before forming the first insulating layer, the method further comprises: forming a lower third insulating layer; and forming a lower second insulating layer on the lower third insulating layer, wherein the first insulating layer is formed on the lower second insulating layer.
 14. The method of claim 12, wherein i) the first insulating layer is formed by a silicon nitride, the second insulating layer is formed by a silicon oxynitride, and the third insulating layer is formed by a silicon oxide, or ii) the first insulating layer is formed by a silicon nitride, the second insulating layer and the lower second insulating layer are formed by a silicon oxynitride, and the third insulating layer and the lower third insulating layer are formed by a silicon oxide.
 15. The method of claim 10, further comprising: forming a blocking layer between the black matrix and the encapsulation layer to prevent the encapsulation layer from being etched by a dry etching process, wherein the encapsulation layer is disposed under the black matrix to encapsulate an organic light emitting diode.
 16. The method of claim 10, further comprising: forming an absorbing layer on the black matrix to absorb at least one of an organic solvent, water, and a liquid for forming sub-pixels.
 17. The display substrate of claim 2, wherein the black matrix comprises: a first insulating layer; a second insulating layer disposed on the first insulating layer; a third insulating layer disposed on the second insulating layer; and a light shielding layer disposed on the third insulating layer, wherein an etched rate of the first insulating layer is greater than an etched rate of the second insulating layer, and wherein the etched rate of the second insulating layer is greater than an etched rate of the third insulating layer.
 18. The display substrate of claim 4, wherein i) the first insulating layer, the second insulating layer, and the third insulating layer are etched by a dry etching process, or ii) the first insulating layer, the second insulating layer, the third insulating layer, the lower second insulating layer, and the lower third insulating layer are etched by a dry etching process.
 19. The display substrate of claim 4, wherein i) the first insulating layer is formed by a silicon nitride, the second insulating layer is formed by a silicon oxynitride, and the third insulating layer is formed by a silicon oxide, or ii) the first insulating layer is formed by a silicon nitride, the second insulating layer and the lower second insulating layer are formed by a silicon oxynitride, and the third insulating layer and the lower third insulating layer are formed by a silicon oxide.
 20. The method of claim 11, wherein forming the black matrix between adjacent pixels comprises: forming a first insulating layer; forming a second insulating layer on the first insulating layer; forming a third insulating layer on the second insulating layer; and forming a light shielding layer on the third insulating layer, wherein an etched rate of the first insulating layer is greater than an etched rate of the second insulating layer, and wherein the etched rate of the second insulating layer is greater than an etched rate of the third insulating layer. 